'use strict';
var utils = require('./utils');
var external = require("./external");
var utf8 = require('./utf8');
var utils = require('./utils');
var ZipEntries = require('./zipEntries');
var Crc32Probe = require('./stream/Crc32Probe');
var nodejsUtils = require("./nodejsUtils");

/**
 * Check the CRC32 of an entry.
 * @param {ZipEntry} zipEntry the zip entry to check.
 * @return {Promise} the result.
 */
function checkEntryCRC32(zipEntry) {
    return new external.Promise(function (resolve, reject) {
        var worker = zipEntry.decompressed.getContentWorker().pipe(new Crc32Probe());
        worker.on("error", function (e) {
            reject(e);
        })
        .on("end", function () {
            if (worker.streamInfo.crc32 !== zipEntry.decompressed.crc32) {
                reject(new Error("Corrupted zip : CRC32 mismatch"));
            } else {
                resolve();
            }
        })
        .resume();
    });
}

module.exports = function(data, options) {
    var zip = this;
    options = utils.extend(options || {}, {
        base64: false,
        checkCRC32: false,
        optimizedBinaryString: false,
        createFolders: false,
        decodeFileName: utf8.utf8decode
    });

    if (nodejsUtils.isNode && nodejsUtils.isStream(data)) {
        return external.Promise.reject(new Error("JSZip can't accept a stream when loading a zip file."));
    }

    return utils.prepareContent("the loaded zip file", data, true, options.optimizedBinaryString, options.base64)
    .then(function(data) {
        var zipEntries = new ZipEntries(options);
        zipEntries.load(data);
        return zipEntries;
    }).then(function checkCRC32(zipEntries) {
        var promises = [external.Promise.resolve(zipEntries)];
        var files = zipEntries.files;
        if (options.checkCRC32) {
            for (var i = 0; i < files.length; i++) {
                promises.push(checkEntryCRC32(files[i]));
            }
        }
        return external.Promise.all(promises);
    }).then(function addFiles(results) {
        var zipEntries = results.shift();
        var files = zipEntries.files;
        for (var i = 0; i < files.length; i++) {
            var input = files[i];
            zip.file(input.fileNameStr, input.decompressed, {
                binary: true,
                optimizedBinaryString: true,
                date: input.date,
                dir: input.dir,
                comment : input.fileCommentStr.length ? input.fileCommentStr : null,
                unixPermissions : input.unixPermissions,
                dosPermissions : input.dosPermissions,
                createFolders: options.createFolders
            });
        }
        if (zipEntries.zipComment.length) {
            zip.comment = zipEntries.zipComment;
        }

        return zip;
    });
};
